This film is an Official Selection of the 2011 Sundance Film Festival. Between 1960 and 1996, Guatemala was immersed in a bloody internal armed conflict that pitted the army against guerrilla groups. More than 200,000 men, women and children were murdered or disappeared during this 36-year-long war, most of them were indigenous.

General José Efraín Ríos Montt led Guatemala’s military government between March 1982 and August 1983 — one of the bloodiest periods of the conflict when there was an aggressive campaign targeting anyone deemed to be supporting left-wing guerrillas.

The 1983 documentary by Pamela Yates, When the Mountains Tremble, showed how the military government, lead by General Montt, killed Mayan civilians. This helped provide key evidence for bringing the indictment, when a Guatemalan court recently convicted former dictator Efraín Rios Montt with genocide for his brutal war against the country’s Mayan people in the 1980s.

(The conviction has been overturned and a new trial is scheduled.) Granito: How to Nail a Dictator tells the extraordinary story of how a film, aiding a new generation of human rights activists, became a granito — a tiny grain of sand — that helped tip the scales of justice.